The use of satellite antennas for reception of television transmissions from satellites has increased rapidly in recent years. The use of satellite antennas allows households to have access to potentially hundreds of television channels, usually many more than are available through local cable television systems. Satellite antennas have also allowed television transmissions to be accessible to rural households which may not have access to cable television. Generally, however, local television station broadcasts are not made available over the satellite transmission. Thus, for households desiring to watch local over-the-air broadcast channels in addition to channels available through the satellite transmission, a second terrestrial antenna is required to receive the local channels.
The use of two separate antennas, satellite and terrestrial, has certain disadvantages. A first is simply the added costs of two antennas versus one, the cost of purchasing two separate antenna support structures, and the attendant costs of setting up and installing the support structures and the antennas. Mounting two separate antennas in two separate locations also requires that separate cables be run from each antenna location to the location of the television receiver, which also increases the set-up and maintenance costs. Furthermore, the mounting of two separate antennas in two separate locations on or around a home may not be aesthetically pleasing.
One approach to solving the problem of two separately mounted antennas has been to mount the satellite and terrestrial antennas at the same location. The satellite and terrestrial antennas may then share the same support structures, as well as much of the wiring necessary to connect the antennas to a television receiver. One example of a combined mounting of a terrestrial and satellite antenna at a single location is the Tennamount.TM. is mounting system, which is designed to attach a conventional terrestrial dipole antenna to the support structure of a large (72"-120" diameter) satellite dish antenna.
More recent satellite television systems receive digital television signals from a satellite, providing higher quality video and sound, and featuring smaller (e.g., 18" diameter) satellite dish antennas which may be conveniently mounted on the wall or roof of a house. The smaller size and more convenient mounting capabilities of such antennas are significant advantages over the earlier, large diameter satellite dishes which typically were mounted separately from the house, such as on a heavy support post mounted in a concrete footing in the ground. The newer digital satellite television systems still typically do not provide access to local television broadcast channels, so that it is still necessary to use a terrestrial antenna in addition to the digital satellite antenna to allow reception of such broadcast signals. An antenna support assembly for supporting both the digital satellite reception antenna and a terrestrial antenna at a single location, where both antennas may be coupled to a single cable leading to the interior of the house, is shown in U.S. Pat. No. 5,604,508. In such a system, two separate antennas, one for receiving terrestrial broadcast signals and the other for receiving the digital satellite signals, are still required.
In one type of antenna system developed to combine a terrestrial antenna into the satellite dish antenna, the reflector dish of the antenna is formed of fiberglass, and a "bow tie" type terrestrial antenna is embedded into the surface of the fiberglass reflector dish. Signals from the satellite signal pick-up of the satellite dish system may be combined with signals from the terrestrial antenna and brought back to the receiver within the house on a common cable. Such systems have a higher manufacturing cost than the satellite antenna alone because of the additional cost of the terrestrial antenna itself and the cost of forming the terrestrial antenna in the reflector dish. Such an antenna design also requires some compromise in the reception obtained with the terrestrial antenna since the reflector dish must be oriented to best receive the satellite signal, which may result in an orientation of the terrestrial antenna which is not optimum for receiving the broadcast television signals.